How many grams is 1 cup of cornstarch?

One US cup of cornstarch weighs approximately 120 grams. This is the standard value used by most culinary authorities and food databases.

Why does the density matter for cornstarch?

Cornstarch is a fine, light powder. The way it is spooned or scooped into a measuring cup affects density. The 120 g/cup value assumes a lightly spooned, leveled cup — the most common method in recipe testing.

Can I use this for cornflour (UK)?

Yes. Cornflour in the UK is the same product as cornstarch in the US, so the same 120 g/cup conversion applies.

What if my recipe uses tablespoons or teaspoons?

There are 16 tablespoons and 48 teaspoons in one US cup. One tablespoon of cornstarch is therefore about 7.5 g, and one teaspoon is about 2.5 g.

Is 120 g/cup accurate for sifted cornstarch?

Sifted cornstarch is slightly less dense. Sifting can reduce the weight to roughly 100–110 g/cup. If your recipe specifies sifted cornstarch, adjust accordingly.

Does altitude affect the measurement?

Cup volume is fixed regardless of altitude. Only baking times and leavening amounts change with altitude — not dry ingredient weights per cup.

Cornstarch Cups to Grams Converter

Enter a cup amount and instantly get the equivalent weight in grams using the standard cornstarch density of 120 g/cup.

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Using the standard density of 120 g per cup for cornstarch.

Cups of Cornstarch

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Summary

This converter translates US cup measurements of cornstarch into grams using the widely accepted density of 120 grams per cup. Whether you are scaling a recipe up or down, or working with a kitchen scale, knowing the exact gram weight helps achieve consistent, accurate results. Simply enter the number of cups and the gram equivalent appears instantly.

How it works

Enter the amount of cornstarch in cups (e.g. 0.5 or 1.25).
The tool multiplies your input by 120 g/cup — the standard density for cornstarch.
The result in grams is displayed immediately, rounded to one decimal place.
Use the quick-select buttons for common fractions (1/4, 1/3, 1/2, 2/3, 3/4, 1).
Click "Reset" to clear the form and start a new conversion.

Use cases

Weigh cornstarch precisely when baking or thickening sauces.
Scale recipes that list cornstarch in cups to metric gram amounts.
Adapt US recipes for kitchen scales that measure in grams.
Verify cornstarch amounts when halving or doubling a recipe.
Convert meal-prep portions to gram weights for nutrition tracking.
Help pastry students and home bakers learn cup-to-gram equivalents.

Frequently Asked Questions

Last updated: 2026-06-11 · Reviewed by Nham Vu